Refrigerator having a secondary cooling means



prifl 24, 1951 w. E. RICHARD 2,550,155

REFRIGERATOR HAVING A SECONDARY COOLING MEANS ll Sheets-Sheet 1 FiledJan. 26, 1946 \N. E. RICHARD April 24, 1951 REFRIGERATOR HAVING ASECONDARY COOLING MEANS l1 Sheets-Sheet 2 11 IIIII IIIHHIIH Filed Jan.26, 1946 April 24, 1951 w. E. RICHARD REFRIGERATOR HAVING A SECONDARYCOOLING MEANS Filed Jan. 26, 1946 11 Sheets-Sheet 3 Jkderzibf (Unis 4April 1951 w. E. RICHARD REFRIGERATOR HAVING A SECONDARY COOLING MEANS11 Sheets-Sheet 4 Filed Jan. 26, 1946 April 1951 w. E. RICHARD 2,550,165

REFRIGERATOR HAVING A SECONDARY COOLING MEANS Filed Jan. 26, 1946 11Sheets-Sheet 5 Aprifi 24, 1951 w. E. RICHARD REFRIGERATOR HAVING ASECONDARY COOLING MEANS ll Sheets-Sheet 6 Filed Jan. 26, 1946 April 24,1951 w. E. RICHARD 0,

' REFRIGERATOR HAVING A SECONDARY COOLING MEANS Filed Jan. 26, 1946 llSheets-Sheet 7 IN VEN T 02 William 8. Richard April 24, 1951 w. E.RICHARD 2,550,165

REFRIGERATOR HAVING A SECONDARY COOLING MEANS Filed Jan. 26, 1946 i1Sheets-Sheet a r INVENTOR.

William @Rz'c/mrd W. E. RICHARD REFRIGERATOR HAVING A SECONDARY COOLINGMEANS April 24, 1951 ll Sheets-Sheet 9 Filed Jan. 26, 1946 m WM %W F. mb M M April 24, 1951 w. E. RICHARD REFRIGERATOR HAVING A SECONDARYCOOLING MEANS Filed Jan. 26, 1946 ll Sheets-Sheet l0 I N VEN TOR'.

Wz'llzhgn /Pz'cizard Y WM 3 W fills Q'Zforney Patented Apr. 24, 1951REFRIGERATOR HAVING A SECONDARY l COOLING MEANS William E.

Richard, Evansville, Ind., assignor to Seeger Refrigerator Company, acorporation of Minnesota Application January 26,1946, Serial No. 643,642

The present invention relates to refrigerators, and is particularlyconcerned with a refrigerator of the type employed for preserving,cooling or freezing foodstuffs in the household.

One of the objects of the invention is the prow vision of an improvedrefrigerator of the class described, which may be provided with suitablecompartments for freezing ice or food products,

and for maintaining them in a frozen condition, and other suitablecompartments for preserving food at another suitable higher temperatureun- V der suitable humidity conditions, so that the foodstufis will notbe dried out in the latter compartment by the removal of the moisturefrom the air, which would otherwise result in removal of moisture fromthe food.

Another object of the invention is the provision of a refrigerator ofthe class described including a primary evaporator system and a closedsecondary system, but in which the secondary I system is not in'heatexchange contact with the primary evaporator but the secondary systemradiates heat fromits condenser to the air in one compartment of therefrigerator, thereby providing a more moderate cooling effect in thatcompartment of the refrigerator which is to be operated at highertemperature and higher humidity than the freezing compartment.

Another object of the invention is the pro vision of an improvedsecondary systemarrangement which simplifies the installation andremoval of the primary refrigeration unit, and which simplifies themanufacture because there is no mechanical connection between theprimary evaporator and the condenser coil of the secondary system.Another object of the invention is the provision of an improvedsecondary system arrangement for cooling the food storage compartment ofa refrigerator which is adapted to raise the temperature of the linerwalls of the cabinet at the cold sections of the liner which surroundthe evaporator, and,'consequently, adapted to reduce sweating on theoutside of the liner so as to substantially eliminatethe sweatingwhichcauses wet insulation at this point.

Another object of the invention is the provision of an improvedrefrigeration system including a primary and a secondary in which theprimary evaporator is so arranged in the uppermost insulated compartmentadjacent the liner, but out of contact therewith, so that thetemperature of that part of the liner is reduced to a temperaturesubstantially equal to the tempera- 11 Claims. (Cl. 62-89) ture of theprimary evaporator, by the transmission of heat from the liner to theprimary evaporator by radiation ofheat from the liner across the spacesbetween the liner and the primary evaporator and by convection aircurrents circulating through said spaces and transferring" heat from theliner to the primary evaporator.

'A further object of the invention is the provision of an improvedrefrigerator construction which is simple, adapted to be manufacturedeconomically, adapted to be serviced readily, and adapted to be used fora long period of time without necessity for repair or replacement of anyof its parts.

Other objects and advantages of the invention will be apparent from thefollowing description and the accompanying drawings, in which similarcharacters of reference indicate similar parts throughout the severalviews.

Referring to the drawings, of which there are six sheets,

Fig. 1 is a view in perspective of a household refrigerator embodyingthe invention.

Fig; 2 is a fragmentary perspective view of the upper part of thecabinet of Fig. 1 with the freezing compartment door open.

Fig. 3 is a top plan view of'the liner of the" cabinet.

7 Fig. 4 is a side elevational view of the exterior of the liner of thecabinet. shown apart from the insulation and outer shell.

Fig. 5 is a rear elevational view of the liner with the outlineof theouter shell shown in dot-dash lines.

Fig. 6 isa side elevational view of a liner, similar to Fig. 4, exceptthat the lower header, and coils are shown as located on the bottom ofthe liner instead of on the back of the liner. 7

Fig. 7 is a view similar to Fig. 6, of another modification in which theevaporator coils are arrangednot only on the bottom but also on the backof the liner at its lower portion. 7

Fig; 8 is a fragmentary horizontal sectional view, taken on a planebelow the upper shelf and above the partition or shelf 36, showing thecontour of the rear edge of the shelf and its engagement with theinsulating plug;

Fig. 9 is a rear elevational view of the evaporator; v l

Fig..10 is aside elevational view of the evap orator, taken from the"left side of Fig. 9.

I Fig. 11 is a diagrammatic developed'plan view of the evaporator, shownin conjunction with theshelfi l 3 Fig. 12 is a diagrammatic verticalsectional view taken on a plane parallel with the door at a point behindthe front edge of the evaporator; Fig. 13 is a diagrammatic sideelevational view showing the arrangement of the compartments andevaporator, taken on a vertical plane parallel to the side wall of thecabinet on the plane of the line I3-|3 of Figure 12.

Referring to Fig. 1, I indicates, in its entirety, a refrigerator of thehousehold type which comprises a cabinet I I having an outer shell I2and an inner shell or liner I3 which is provided with a forward openingclosed by a door I5.

The outer shell may be made of metal, such as sheet metal, suitablyornamented 'or' covered by paint or enamel, and the inner shell or linerI3 may also consist of a suitable sheet metal member, its walls beingpreferably covered with a coating of vitreous enamel on the inside andoutside for the purpose of promoting sanitation and preventing rusting.

The liner I3 is supported from the outer shell I2 by means of insulatingbreaker strips I6 of conventional construction, and any suitable form ofinsulation may be placed between the outside of the liner and the insideof the outer shell I2.

The door it may be of similar construction, with a pair of shells spacedfrom each other and filled with insulation, such as rock wool, theshells being secured together by suitable breaker strips I6.

At the lower end of the cabinet H there is an insulating wall, theforward edge of which is indicated at H, formed by the bottom of theliner and a transverse plate of the shell and insulation between them,and the space below the insulating wall Il may be occupied by a drawerI3 mounted upon suitable guides. v

V The liner I3 comprises a top wall I9, a pair 'of side walls 20, 2|, abottom wall 22, and a rear wall 23, the latter being preferably providedwith a rectangular opening 24 adjacent the top of the liner forinsertion of a removable primary evaporator unit. I

The primary refrigeration system of the cabinet is preferably of. thetype disclosed in the prior application of Russell W. Ayres, Serial No.494,600, filed July 14, 1943, now Patent No. 2,445,988, granted July 27,1948, entitled Refrigerator Construction With Removable RefrigeratorUnit, in that this unit is preferably mounted upon an insulating plug 25which supp'ortsthe evaporator on the inside of the cabinet and isinsertable into the opening 24 of the liner, and carries upon its rearside suitable mechanism-of the motor compressor-condenser type, thedetails of the latter being substantially as disclosed in theapplication above mentioned. The primary evaporator is indicated'in itsentiretyby the numeral 26, and it preferably -includes an evaporator ofthe two-sheet type, one of the sheets being embossed to provide suitablegroovesforming conduits for the passage of refrigerant both in 'thebottom wall 21 of the evaporator and the side wall 28.

Therefrige'rant conduits in the sidewall may communicate with atransverselyextending larger header 29, also formed by embossing groovesin both of the sheets which form the evaporator, and the header 29 maycommunicate with another upper header 30 through "a plurality-ofembossed conduits between the plates of the side wall 28.

Referring to Fig. 11, this is a diagrammatic bend at the bottom of thedeveloped plan view of the shelf and the external walls of theevaporator 26, showing the course of the refrigerant. The refrigerant isbrought in at the point 33a and introduced into the sinuous coils 35 ofthe shelf 33, which extend back and forth under the shelf, andthereafter communicate at 331 2,1with additional sinuous coils 3|aformed in the wall "3| and part of the bottom of the evaporator 26.

The line AA, Fig. 11, indicates the point of I side wall 3 I. The lineBB, Figure 11, indicates the point of the bend at the bottom of the sidewall 28 of the evaporator 2B.

The sinuous coils visible in Figure 2,

3Ia, in side wall 3|, are not because they are on the outinside sheetfiat. From the series coils 3Ia the refrigerant goes to a distributingheader I02, which has a multiplicity 'of distributing conduits |Il|communicating with the parallel conduits I03, at the U-shaped ends ofthe conduits I03.

The conduits I03 are formed in one or the other of the sheets whichconstitute the wall 28, and they extend upward and communicate with theheader 29-, which in turn communicates through a multiplicity ofconduitsI04, with the header 30.

The take-off from the header 30 is shown at I05, and the supporting tabs32, which support the front end of the evaporator from the ceiling ofthe liner, areshown in Figure ll.

The side walls 28 and 3| of'the evaporator 26 may be secured to the top'wall I9 of the liner by inwardly turned attaching flanges 32 'andsuitable screw-bolts threaded into threaded members carried by the linerwall I9, so that, in addition to being supported by the plug 25, theevaporator is supported at its forward upper edges from the top linerwall I9.

The evaporator '26 is also preferably provided with a freezing shelf 33which may consist of a sheet metal member presenting an' upper plainsurface for engagement with the ice trays 34 and having on its lowerside a plurality of transversely extending tubular copper coils 35 whichare soldered to the shell 33 for intimate heat exchange contacttherewith.

The refrigerant from the compressor may be brought first to the coils 35of the shelf 33 and thence to the embossed conduits in the bottom 21 ofthe evaporator, which terminate in the header 29 which .communicateswith the header 30, the latter avoiding all possibilityof turbulence ofliquid in the uppermost header which is connected to the inlet side ofthe compressor.

The back of the evaporator unit 26 is adjacent to the forward metal wallof the plug 25, while the front of the evaporator unit may 'be providedwith a suitable metal door 3.6 pivotally mounted on the hinges at itslower edge and provided with a main body .3! and attransverse borderflange 38 which is adapted, when the door is closed, to overlap the.outer forward edge of the evaporator walls 21, 38, 3|. The door 36 maybe. supported in horizontal position when open by pairs of links 39,liL'pivoted together and each pair having its ends pivotally secured tothe door 36 and to each side wall 28or=3| at 4|.

The door 35 may be held in closed position by the friction-of its hingesand-links for engagement of its border flange with the side walls, andit :iS held inopen-position, asshown in Fig. .2,

, from each other by the ing only relatively narrow spaces 42, 43between the side walls 26, 3| of the evaporator and the,

walls 26 and 2| of the liner, to which the air in the uppermostcompartment has access. The space inside the liner is preferably dividedinto an upper compartment 44 and a lower compartment 45 by an insulatingpartition or shelf 46.

The shelf 46 may consist of a pair of complementary telescoping metalshells, each of which has a main body plate 41, 48 and a border flange49, 56. The border flange 56 of the upper member of shelf 46 may beseparated from the border flange 49 and insulated therefrom by a fibrebreaker strip which is frictionally heldbetween the telescoping flanges4-9 and 56, and the interior of the shelf 46 may be filled with suitableinsulation, such as rock wool.

Referring to Fig. 8, 25 indicates in its entirety the insulating plug,which isinsertable in the rear opening 24 in the liner, and. whichcarries the evaporator 26. This plug maybe made of a pair of pressedmetal shells 25a and 25b joined together by insulating breaker strips250.

As the lower part of the plug is located substantially at the shelf 46,the rear edge of the shelf 46 has a curved outline, as indicated at 46ain Fig. 8, thus separating the compartments 44 and 45 and preventing aircommunication between them at the back of the shelf.

Thewidth of the shelf 46 may be such that its lateral edges engage theinside of the liner walls 26, 2 I, and its rear edge engages the rearwall 23 of the liner, while its front edge extends into a position whichhas a clearance with respect to the rear side of the door [5. The shelf46 may be supported in its position shown in Fig. 2 by a plurality ofmetal studs threaded into suitable threaded members carried on theoutside of the liner walls 26 and 2 Land having threaded bores,registering with apertures in the lined walls.

The partition 46 may also be provided with guides for supporting aporcelain enamel covered drawer 52 for storage of foodstuffs which areto be kept separate from the rest of the food in'the compartment l4.

The two compartments 44 and :4 are separated fact that the partition 46engages the lower edge of the door 36 when the door is closed, and themajor portion of the air from the lower compartment is thus excludedfrom the upper compartment, although there may be some leakage betweenthe spaces 42 and 43=adjacent the primaryevaporator 26 and the lowercompartment, since the insulated partition .46 is not provided withsealing means for engagingthe door [5. This access of the air fromthe'lower compartment to the upper compartment and to part of the primaryevaporator may-be utilized for removing, from the lower compart ment l4a predetermined'amount of the moisture in the air for reducing therelative humidityi While it is desirable that the air of the food tureconditions in the storage compartment l4.

Thus the access of air from the lower food storage compartment to thelimited spaces 42, 43, at the sides of the evaporator, may bepredetermined to reduce the relative humidity of the air of the,

lower compartment by the condensation of a predetermined amountof themoisture.

Referring to Figs. 3, 4 and 5, these are diagrammatic illustrations ofthe liner, which show the arrangement of the secondary system forfacilitating the cooling of the compartment 45. The liner is preferablyprovided on its top with a top header 55 which may extend forwardly andbackwardly across the top wall IQ for the purpose of charging andpurging the system, and this header is preferably provided with asuitable fitting 56 at one end for communicating with a charging pipe 51which may be removed when the system has been charged.

The top header 55 comprises a relatively large copper tube whichcommunicates with a plurality of laterally extending refrigerantconduits comprising the copper tubes 586| on the left, Fig; 3, and 62-65on the right. The conduits 58-65 may also consist of copper tubes whichare brazed or soldered to the top header 55 and communicate therewith,andconduits 58-6I ex-. tend laterally on the top Wall l6 of the liner toits lateral edge where they are? all bent downwardly to extenddownwardly along the side wall2l. 5 a

The downwardly extending portions of these pipes are indicated by thenumerals 66-69. The

conduits 68-65 and their extensions are preferably uniformly spaced fromeach other, and prefthe liner wall. Thus the first conduit 58 is spacedfrom the back wall by approximately the same distance as the spacingbetween the conduits, and the same is true of the spacing of theconduits 6 land from the front wall or door opening.

In order to cool the back wall 23 of the liner adjacent the lowercompartment 45, the conduit portions 66-69 are bent with an easy bend attheir lower ends, but these conduit portions 6669 are made successivelyshorter so that the substantially horizontally extending portions 10-13are also spaced substantially equally from each other on the side wall26 and the back wall 23. The easy bends are indicated by the numeral 14.

At the rear wall 23 of the liner the conduit portions 16-73 are bentlaterally in such manner that they extend laterally across the rear wall23 and in contact therewith, as shown in I Fig. 5. It should be notedthat the rearwardly storage compartment 45 be maintained at a higherhumidity than the air in the freezingcompartment 44, it is also truethat excessive humidity may result in the lower compartment, unlesssomeof themoisture is removed as the reduction in the temperature of theair which comes infrom the outside increases its relative humidity.

when this air has beenreduced to. :thete'mperae;

extending portions 1013 slope downwardly toward the back, and the rearwall portions 14-Tl also slopedownwardly toward the bottom header 18,with which the conduit portions i i- 11 communicate on both sides of thebottom header 18.

The purpose of the bottom header is to equalize the refrigerant level inall of the conduits of the secondary system, and it may be closed atboth ends.

The conduits forming an extension of top conduits 62-65 on the rightside of the liner, Fig. 3, may be arranged exactly as described withrespect to the left side, the whole system being a closed container forrefrigerant.

All of the conduits of the secondary are prefarably in heat conductingcontact with the Walls of the liner, and they may be held in engage-'ment with the walls of the liner by a'plurality of channeled metalcross-bars 19, 80, 8| and 82,

7 on each side of the liner. The cross-bars are. provided with aperturesfor receiving the screw-bolts 83 which pass through the crossbars, andare threaded into threaded members carried by the liner Wall, such as,for example, nuts soldered to the liner wall.

The cross-bars are provided with partially circular grooves 84, Fig. 5,for receiving the outer side of the conduits and for holding theconduits in definite spaced relation while the crossbars clamp theconduits into engagement with the exterior of the liner.

In order to further assure the heat conducting contact between theconduits and the liner at points between the cross-bars, the conduitsare preferably cemented to the liner by an initially plastic, adhesivecompound 85, 'such as asphaltum or a bituminous composition, which;

holds the conduits uniformly in contacting engagement with the walls ofthe liner. This cementitious compound is used because the liner iscovered with porcelain.

The heat conductivity of the cementitious compound may be increased byincorporating in it a multiplicity of metallic particles, such asaluminum filings, whichaid in conducting the heat from the liner to thsideportions of the copper conduits and increase the effective heattransfer between the conduits and the liner.

In some embodiments of the invention the liner might be made of a metal,suchas stainless steel, which need not be coated with porcelain enamel,and in such case the copper coils would be soldered to the exteriorwalls of the liner. a The closed secondary system on the exterior of theliner hasits air and other non-condensible gases evacuated from it, andafter being dehydrated by successive evacuation and heating, thesecondary system is charged with a predetermined amount of suitablerefrigerant, such as dichloro-difluoromethane (CC12F2).

The operation of the refrigerator system is as follows:

The primary evaporator 26 is supplied with liquid'refrigerant in theusual manner, the vaporized refrigerant being pumped off by the rotarycompressor and condensed by the condenser for return to the primaryevaporator.

The major part of the upper compartment space 54 is occupied by theprimary evaporator, the interior of which provides an upper freezingshelf for ice trays and a lower freezing space for. freezing food orstoring it at below-freezing temperatures.

' The upper wall portions of liner walls 20 and 21 adjacent the airspaces 42 and 43 are cooled by radiation from the liner walls to theevaporator and by convection of heat by theadjacent air, so that theseportions of the liner walls are at a temperature which closelyapproximates that of the primary evaporator.

In the operation of the secondary system, the food and air in the lowercompartment 45 transmit heat to the lower portions of the side walls 20and 2! and to the back wall 23, which heat is conducted to the secondaryrefrigerant conduits, causing the refrigerant to vaporize and topassupward in the conduits to the upper ends of the conduit portions E-B9and to the conduits 58-65 and header E on the top wall 19.

The vaporized refrigerant in the secondary system is condensed .toliquid which runs back down the conduits to the bottom of the secondarysystem through the. same conduits, but in some embodiments of theinvention separate return pipes might be used.

At the same time, heat is conducted upwardly in the liner walls 20 and2! from the warmer lower portions of these walls to the upper colderportions of the walls adjacent the air spaces 42 and 43. This increasesthe cooling effect of the secondary system, in particular, at the upperpart ofthe compartment 45, where the warmer air tends to accumulate.

vIt should be understood that the specific location and construction ofthe secondary coils may be Varied, as the coils may be placed on thebottom of the liner instead of the rack, or they may be S-shaped coilsextending around as many sidesof the.liner as desired.

.As distinguished from the secondary systems of the prior art,condensation takes place in the present secondary system over a largersurface, at higher temperatures, instead of on the smaller contactsurface on the primary evaporator at a lower temperature, as is the casewhere the secondary is in direct thermal contact or direct heatexchanging relation with the primary.

In the present systemthe larger condensing surface is provided by theclose proximity of the wider evaporator to the upper liner wallswhichconduct heat from the adjacent secondary coils.

The present secondary system greatly simplifies the installation andremoval of the primary refrigeration system through the opening 24, asthere are no mechanical connections whatever between the primary systemand the secondary system.

The manufacture-of the secondary and the primary systems is simplifiedand made more economical because there is no mechanical connectionbetween the primary evaporator and the secondary coil. The temperatureof the liner walls at the cold sections surrounding the evaporator israised, and this consequently reduces sweating on the outside of theliner, which sweating would be undesirable, as it causes wet insulation.

Referring to Fig. 6, this is a modificationin which the secondaryrefrigerant conduits are connected with a header at the top similar tothe header 55, previously described. The conduits 66B9 are arranged topass across the top of the liner 19 in substantially the same way asdescribed with respect to Fig. 4, and. are clamped to the sides byclamping members 19 and 80, in the same way.

In this modification, however, instead of these conduits being bentlaterally at 14, they extend straight down to the bottom 22 of the linerand are bent at substantially right angles at the lower corners andextend across the bottom to the centrally located manifold 90. Thismanifold extends from front to back of the liner and is preferablycentrally located on the bottom.

7 Referring to Fig. 7, thisis another modification in which the upperpart of the secondary and liner are arranged in the same way asdescribed with respect to Fig. 4. This modification is provided with anangular manifold 91 which extends rearwardly across the bottom 22 to theback of the liner, where it is bent upwardly at 92 and is provided witha vertical portion 93 on the back of the liner.

82 again indicates one of the clamping members. In this case the twoforemost refrigerant conduits 66, 61 extend downwardly intocommunication with the bottom portion of the manifold 9f in the samemanner as described with respect to these conduits in Fig. 6.

The two conduits 68, 69 on each side of the box are bent rearwardly at14 with an easy bend,

andextend to the back of the box where they that a l of the conduitstend to drain into the manifold 9|. v

With regard to the proper level of liquid reifrigerant in the secondaryconduits, the liquid level should preferably be as high as, or higher tthan, the highest connection between any of the laterally locatedconduits and the lowermost header. The level of the liquid refrigerantdetermines, at least approximately, the cooling area below whichevaporation takes place, although some evaporation may take place abovethe normal level due to the bubbling and boiling. The operation of thesemodifications is substantially similar to that of the preferredembodiment of the invention.

While I have illustrated a preferred embodiment of my invention, manymodifications may be made without departing from the spirit of theinvention, and I do not wish to be limited to the precise details ofconstruction set forth, but desire to avail myself of all changes withinthe scope of the appended claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States, is:

1. In a refrigerator, the combination of an insulated cabinethaving anouter shell and a liner of heat conducting characteristics, said linerforming an interior cabinet space which is divided b an insulatedpartition into upper and lower compartments, a primary evaporator unitlocated in the upper one of said compartments spaced from the walls ofthe liner, but closely adjacent to said walls, said evaporator beingadapted to provide a freezing temperature in said upper one of saidcompartments and by radiation and convection of heat from the liner tothe evaporator by the adjacent air to cool the adjacent walls of theliner, a secondary refrigeration system comprising a closed systemhaving a plurality of refrigerant passages, said refrigerant passagesextending along predetermined walls of the liner from points adjacentthe primary evaporator to the lower parts of the liner wall for coolingthe side walls and rear wall of the liner at a higher temperature thanthat existing in the other compartment of the refrigerator, saidrefrigerant passages extending upwardly and downwardly on the side wallsof the liner and being curved to extend across the back of the liner tocool that portion of the back of the liner at a point remote from theprimary evaporator, said passages being provided with a manifold joiningthe passages at the lowermost point of said secondary system.

2. In a refrigerator, the combination of an insulated cabinet having anouter shell and a liner of heat conducting characteristics, said linerforming an interior cabinet space which is divided by an insulatedpartition into upper and lower compartments, a primary evaporator unitlocated in the upper one of said compartments spaced from the walls ofthe liner, but closely adjacent to said walls, said evaporator beingadapted to provide a freezing temperature in said upper one of saidcompartments and by radiation and convection of heat fromthe' liner tothe evaporator by the adjacent air to cool the adjacent walls of theliner, a secondary refrigeration system comprising a closed systemhaving a plurality of refrigerant passages, said refrigerant passagesextending along predetermined walls of the liner from points adjacentthe primary evaporator to the lower parts of the liner wall for coolingthe side walls and rear wall of the liner at a higher temperature thanthat existing in the other compartment "of the refrigerator, saidrefrigerant passages extending upwardly and downwardly on thesidewalls'of the liner and being curved to extend across the back of theliner 'to cool that portion of theback of the liner at a point remotefrom the primary evaporator, said passages being provided with amanifold joining the passages at the lowermost point of said secondarysystem, and havinglanother manifold joining said passages at theuppermost point of said secondarysystem.

3. In a refrigerator, a secondary cooling system comprising a liner anda plurality of con duits for refrigerant extending across the top of theliner and downwardly on each of the side walls of the liner, saidconduits being turned backwardly and extending across the back of thliner at the lower part of said liner.

4. In a refrigerator, a secondary cooling system comprising a liner anda plurality of conduits for refrigerant extending across the top of theliner and downwardly on each of the side walls of the liner, saidconduits being turned backwardly and extending across the back of theliner at the lower part of said liner, said conduits being clamped tothe outer wall of the liner by a plurality of transversely extendingclamping members.

5. In a refrigerator, a secondary cooling system comprising a liner anda plurality of conduits for refrigerant extending across the top of theliner and downwardly on each of the side walls of the liner, saidconduits being turned backwardly and extending across the back of theliner at the lower part ofsaid liner, said conduits being clamped to theouter wall of the liner by a plurality of transversely extendingcla'nping members, and being also held in heat conducting contact withthe liner by an init ally plastic adhesive compound.

6. In a refrigerator, a secondary cooling system comprising a liner anda plurality of conduits for-refrigerant extending across the top of theliner and downwardly on each of the side walls of the liner, saidconduits being turned backwardly and extending across the back of theliner at the lower part of said liner, said conduits being joined by anupper header conduit located between the side walls and extending acrossthe top wall of said liner.

7. In a refrigerator, a secondary cooling sys tem comprising a liner anda plurality of conduits for refrigerant xtending across the top of theliner and downwardly on each of the side walls of the liner, saidconduits being turned backwardly and extending across the back of theliner at the lower part of said liner, said conduits'being provided witha header conduit located on the'back wall and extending upwardly anddownwardly to communicate with all of said conduits which extend acrossthe backwall.

8. In a refrigerator, a secondary cooling system comprising a liner anda plurality of conduits for refrigerant extending across the top of thliner and downwardly on each of the side apron-e5 tem comprisinga" linerand a'pluralityzof conduits for refrigerant extending, across the topof:the liner and*downwardly= on; each of the side walls off th liner, saidconduits being turned backwardly and lextendingiacross the-back- -of theliner at the lower part of-said liner, ,saidi conduits .being providedv"with. a: header. conduit located; on the back wall and extendingupwardlyanddown- I wardlyto -communicate with. all of said conduitswhich extendacross'the backwall', and saidconduits also being joined bya: top header extending across the top wall and: communicating-1 withthe conduitsata point betweenthe sidewalls.

.10. In a refrigerator, a secondary cooling-system comprising -a-- linerand a plurality of. conduits for refrigerant, the said conduitscommunieating with: a" header at the: top of the-? liner and extendinglaterally across the: top and=-downwardlyon' each of theesidewalls- -ofthe liner, predetermined of said" conduits on each side extendingdownwardly to the: bottom of Y the liner and extending. transversely ofsaid bottom into communication with. similar conduits from: the otherside of'theliner, and: others of said conduitsJbeingbent backwardlyandlextending toi-the rear of, said-liner where the..1atter:=conduitsextend into communicationwith each-other.

11.. In..a refrigerator, alsecondary cooling systemcomprising a linerand aplurality of conduits for. refrigerant, the said conduitscommunicating with arheader at the top of. the liner and extending,laterally across the top and downwardly on each of the side walls ofltheliner, predetermined of saidrconduitson. each side extending downwardlyto. the bottom of the liner and extending transversely of said bottominto communication with similar conduits-from the-other side of theliner, and others of said-conduits being bent backwardly and. extendingto the rear of said.1iner where t-he'latter conduits: extend intocommunication with each other, and a header extending, rearwardly acrossthe: bottom of. the linerv and upwardly onthebacleof the liner. andcommunicating withall of. saidconduits at their lowermost. end portions.

WIILIAME. RICHARD.

REFERENCES CITED:

The following references are of record in the file of this patent UNITEDSTATES PATENTS

